Twin-screw submarine boat.



No. 878,752. PATENTED-FEB} 11, 1908.

I L. Y. SPEAK. TWIN SCREW SUBMARINE BOAT.

11221101111011 FILED AUG. 1, 1906.

2 SHEETS-SHEET 1.

PATBNTED FEB. 11, 1908. L. Y. SPEAK.

TWIN SCREW SUBMARINB BOAT; APPLICATION IiLEI) AUG.1, 1906.

2 SHEETS-SHEET 2.'

UNITED STATES PATENT OFFICE.

LAWRl-INOE YORK SPEAR, O1 QUINCY, MASSACZIUSET'IS, ASSIGNOR TO ELECTRIC BOAT OOMlANY, NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

TWIN-SCREW SUBMARINE BOAT.

Specification of Letters Patent.

Patented Feb. 11, 1.908.

' Application filedAugust 1, 1906. Serial No. 328.734.

and useful Improvements in Twin-Screw Submarine Boats; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of the invention is to providea submarine or submergible boat, having the usual substantially circular cross sectional construction, with twin screws, in order to secure for this type of boat the obvious and well known advantages of double screw propulsion. To effect this object and to avoid out-board bracket bearings for the screw shafts, the stern section of the boat is gradu* ally reduced. or diminished vertically, from the substantially circular cross section of the major part of the hull, so as to finally merge, through gradually flattening elliptical cross sections, into a stern frame having substantially parallel sides, within which frame are formed, the end hearings for the screw shafts.

Inasmuch asthe departure from the substantially circular cross section of the hull will tend to reduce the stiffness of the stern section and to impair its capacity to sustain heavy pressure due to submorgence, the invention also contemplates the provision of means for counterbalancing the external pressure of submergence, whenever necessary, so as to completely relieve the stern section from all tendency to collapse when the boat is submerged.

In the accompanying drawings; Figure 1 is a vertical longitudinal section through the aft )ortion of a submarineboat, showing the application of the invention. Fig. 2is a horizontal longitudinal section on line 22 of Fig. 1. Figs. 3, 4, 5, and 6 are sections taken on lines 3-3, 44, 55, and 6--6, respecf tively of Fig. 2.

Referring to hull of a submarine or submergible boat, which, according to the generally accepted principles of engineering construction is built upon substantially circular frames 1) covered with shell plating 0, so that a transverse cross section of the boat taken at'any station, is substantially circular. The purpose of this generally circular construction 1s to render the drawings a indicates the 'y' are formed in lateral skegs l' it has been customary to employ'but one.

screw or propeller for the reason that where the circular construction was carried aft to the stern, two screw shafts could not be installed without having the latter pass through the sides of the hull and be supported in outboard bearings orfbrackets, which is a construction not suitable for boats-of this type.

According to the present invention it is possible to preserve the generally circular cross sectional construction, of the major, portion of the hull, and at the same time to provide the boat with twin screws, the shafts of which shall be journaled wholly within the boat. To efiect this result the stern scc tion of the boat is given a form which merges or diminishes from the substantially circular cross section of the major portion of the boat, through gradually flattening elliptical cross sections into a stern framef having substantially horizontal sides, and forming the end bearings for the two screw or propeller shafts The hull is maintained substantially circular in cross section, aft to such point as will admit of the gradual and fair merging of the remaining aft section into the substantially horizontal stern frame. The desired shape 'of the hull, in this stern section is effected by means of substantially elliptical frames, the major axis of'the ellipsis being in a horlzontal plane and the vertical axis of the successive frames being reduced so that the frames are graduallyflattened or reduced vertirallyuntil at the ultimate aft section they merge into the stern frame f which has substantially horizontal sides and is rovided at its ends with enlarged bosses to 'ormbearings for the propeller and shafts, said frame f constituting; in effect, a spectacle frame.

The shell platmg 'e is continued aft over the stern section and terminates in the stern or spectacle frame 1' to which it is riveted. Formed as an integral part of the casting or forging, which constitutes the spectacle frame, are the middle bearings it for the steering rudder i and the diving rudders j. The out-board hearings of the diving rudders olating and secured to the shell as illustrated. he steering rudder & finds its out-board l formed of.

i to Withstand the heavy pressure form of the frames becomes exaggerated, a water-tight bulk head Z is applied,

which may be of plating or a casting sufiiciently stifi and strong to resist the pressure due to any depth of submergence. This bulkhead materially assists the elliptical frames between the same and the first circular frame in stiffening the forward part of-the stern section against deformation or colla se due to the pressure ofsubmergence T e portion of the hull abaft this bulkhead is not intended mergence, although it maybe amply stron to resist the pressure to which it is subjecte when the vessel is operating on the surface. If it is not desired to utilize the space behind the bulkhead Z, the danger of the section collapsing under the pressure of submergence may be avoided by making the section nonwater-tight that is to say, by opening the sectionto the sea so that the ressure inside and outside will be equalize atall times. This may be effected either by providing the sections with permanent openings to the water entering and leaving the sections freely, or it may be effected, when desired, by valves placed at the top and bottom of the section and controlled from other ortions of the boatx It isgenerally preferre ,howcver,

to utilize the space in-the stern section of the boat for the storage of fuel in the form of oil and the like, under which circumstances the counterbalancing of the pressure of submergence may be effected by means ofthe fittings illustrated in Fig. 1, whereby the fuel may be admitted to the stern section behind the bulkhead, the latter may be vented at'the top and be opened at'the bottom to the pressure of the-surrounding water. I q represents a vent-pips, (passing from the storage compartment e 'n thebulkhead l, whichvent-Iiipe is controlled by asuitable cook or valve 1'. The'fuel is admitted to the compartment through a filling pi )e t which 56 is controlled by a valve u operate by a suitthe beat.

abl'e handle v'located within the interior of A 'ipe o communicates with the Interior of their,

rank at one end and with the sea at the other, and is controlled by a valve so as to admit or exclude the sea water from the interior of the stern sectiorrl Be? due to sub-.

admit of fore submergence of the boat the valivep is 1 opened, thereby opening "communication between the stern section and the sea, and in case the space is not entirely full of oil or other fuel, either one 'of the valves 1 or u in water, the valve 4 or a which has been opened is closed, while the valve 1) is allowed to remain opened in order to. freely admit the. water of submergence and equalizing the pressure on the inside and the outside of the section. This not only prevents any change in the wei ht of the vessel when submerged, but also absolutely precludes any danger of collapse of this portion of the hull; The propeller. shafts may, of course, 'be run through this'stern section in the usualform, in stem tubes not shown.

What I claim is:

1. A submarine or submergible boat, having a hull OfZSUbStiLIltifldlY circular cross section for the'greater part of the length thereof, a ern sect on merging or dimimshing from such substantially circular cross section through gradually flatteningx elliptical cross sections into a stern frame aving substantially horizontal sides, a water-tight bulkhead in the forward part of said stern section, and means for admitting pressure to said stern section to counterbalance the external pressure of submergence.

2. A twin screw submarine or submergible boat, having -a hull of substantially circular cross section for the greater part-of the length thereof and a stern section merging from said substantially circular cross section into a horizontal spectacle frame forming the bearings for the shaft of said twin screws, a water-tight bulkhead in the forward'part of said stern section, and means for admitting ressure to said stern section to counterbalance the external pressure of submergence;

3. A twin screw submarine or submergible boat, having a hull of substantially circular cross section for the greater part ofthe length thereof, and a stern section merging from a horizontal spectacle, frame forming the bearings for the shaft of said twin screws, a water-tight bulkhead in the forward part of said stern section, and-af' valved, inlet to said stern section, toadmit the water of submergence thereto to balance the internal and external pressures on said stern section.

,I-n testimony whereof I aflix my signature, in presence of two witnesses. v LAWRENCE YORK SPEAR.

Witnesses: i

' F. L. BRAKE,

Wt-D'. F sLER.

the pipes g and t, respectively, may belopened' to vent the compartment and permit it to fill. When the space is entirely filled With oil and said substantially circular cross section into 

